Rapid confirmation method of food poisoning caused by Bacillus cereus cereulide in rice and flour products

Abstract

To develop a method for rapid determination of Bacillus cereus cereulide in rice and flour products by ultra-performance liquid chromatography-tandem mass spectrometry, providing emergency measures for food poisoning caused by cereulide. Single rice and flour samples were extracted with acetonitrile aqueous solution, salting out, after centrifuged and filmed, the organic phase was directly determined. The complex matrix samples fried rice and noodles were extracted with acetonitrile aqueous solution, cleaned up with HLB column, a ACQUITY UPLC Peptide BEH C_(18) 300Å column(2.1 mm×100 mm, 1.7 μm)was used for liquid chromatography separation, multiple reaction monitoring(MRM) mode was used for detection in electrospray ionization with positive ion mode, and quantified by the solvent standard curve method. At the spiked level of 0.5, 1.0 and 5.0 μg/kg, the recoveries of cereulide in negative steamed rice, steamed bread and noodles samples were 87.4%-98.3%, and the relative standard deviations were 1.4%-4.2%. At the spiking levels of 1.0, 2.0 and 5.0 μg/kg, the recoveries of cereulide in the negative samples such as fried steamed rice and fried noodles were 89.5%-99.3% with the relative standard deviations of 1.1%-7.5%(n=6). The detection limit of cereulide was 0.2-0.3 μg/kg, and the quantification limit was 0.5-1.0 μg/kg. The established method was applied to the detection of the actual samples causing food poisoning in a certain place in Beijing. The content of cereulide in poisoned food samples was 1287-7398 μg/kg, the content of cereulide in two raw materials cold noodles was 0.4 and 9.4 μg/kg. The method is simple, rapid, high sensitivity and accurate, and can realize the rapid treatment of food poisoning caused by cereulide.